1. Field of the Invention
This invention relates to fuse holders and methods for manufacturing thereof.
2. Description of the Prior Art
One type of fuse holder known in the prior art has a fuse receiving barrel of electrically insulating material such as plastic. At one end of the barrel is attached a first contact which conductively engages one end of the cylindrical fuse positioned in the barrel. A ferrule-like, conductive second contact, having opposing J-shaped slots therein, is disposed near the other end of the barrel. Both of the contacts eventually are connected to the circuit to be protected by the fuse. The fuse holder also includes a cap having a cylindrical, conductive connector receiving the other end of the fuse. The connector has a pair of outwardly extending tabs which are received in the slots of the second contact forming a bayonet connection between the connector sleeve and second contact. A spring disposed within the connector normally maintains the bayonet connection and thereby the conductive engagement between the fuse and the first contact and the connector and second contact. To protect the user of the fuse holder from receiving a shock from the second contact an insulating sleeve is interposed in the barrel, between the connector and the second contact, leaving only the bayonet connection to conductively interconnect the fuse to the second contact.
One notable drawback of the above described fuse holder is that the circuit through the fuse can be interrupted. Should force come in contact with the cap forcing the tabs out of engagement with the slots, conductive engagement therebetween is broken. Another drawback is that assembly of this type of fuse holder requires many steps and several parts including the insulating sleeve. This in turn increases the cost of manufacturing.
The Wallner U.S. Pat. No. 4,072,385 issued Feb. 7, 1978 describes a type of fuse holder having a second contact with an integral spring to maintain conductive contact between the component and the second contact should the cap be forced inward of the barrel. This type of fuse holder also requires the insulating sleeve and the multi-piece construction described above.
It is known in the prior art that cylindrical fuses, of the type having conductive ends, are manufactured in basically two sizes. One size, the American-type fuse, is 1.25 inches (31.75 mm) long and 0.25 inches (6.35 mm) in diameter. The other size, referred to as the European-type fuse, is 0.79 inches (20 mm) long and 0.20 inches (5 mm) in diameter. Accordingly, fuseholders should be adaptable to accommodate either the American-type fuse or the shorter European-type fuse.